The present invention relates generally to apparatus and methods for use when developing wound coils and, more particularly, to apparatus and methods for handling and locating predetermined segments of magnet wire used for developing coils of dynamoelectric machines--especially electric motors.
During one process for winding coils for dynamoelectric machines (e.g., electric motors) magnet wire is fed from a supply along a predetermined path to a wire dispenser which is utilized during generation of winding turns for one or more coils in two or more coil groups which, subsequently, are disposed in slots of the magnetic core.
One type of coil winding operation has become known as "wind and shed" or "shedder" winding and may be carried out, for example, with equipment of the type illustrated in the above-referenced related application or any of the above-referenced patents. In order to more clearly point out what is considered by applicants to be their invention, extensive details of winding equipment are not specifically illustrated or specifically described herein and for that reason, the entire disclosures of all of the above-referenced patents and the related application are specifically incorporated herein by reference.
The shedder type of coil winding operation is generally accomplished by holding a coil form assembly in a winding plane while turns of a first size of wire are developed thereabout. Then, while turns continue to be generated, at least part of the form assembly is jumped axially relative to the winding plane and a winding turn receiving mechanism. Alternatively, of course, the receiving mechanism and coil forms may rotate or the wire dispensing and receiving mechanisms may be jumped relative to the coil core assembly. When any of the just-mentioned approaches are followed, however, a plurality of winding turns will be generated in substantially one given plane. Depending upon the speed of winding turn generation (i.e., the winding flyer rpm), and the size and type of material used in the winding, oscillation or flutter of the wire will occur during the winding operation. Excessive oscillation or wire flutter may in turn interfere with smooth and uniform shedding of wire turns. One of the approaches that has been long recognized for the purpose of minimizing or controlling wire flutter or oscillation is the use of a masking plate as shown, for example, by masking plate 82 in the above-referenced Smith U.S. Pat. No. 3,510,939.
When at least two coils groups ("coil group" also being referred to as a "pole" in published literature) are formed in a turn receiving mechanism prior to transfer to a magnetic core structure, one of the more common approaches is to develop a first coil group in the mechanism or receiver; index the receiver; and then wind a second plurality of turns so that a second pole or coil group is established in the receiver. It will be understood that the winding direction (e.g., relative flyer rotational direction) may be reversed from one pole to the next. Moreover, it will be understood that the receiver may be indexed in either a clockwise or counterclockwise direction about its longitudinal center. In any of these cases, it has now become the general practice to provide a mechanism and methods whereby a segment of an interpole (or intercoil group) lead wire is grasped after one pole (or coil group) has been established in the receiver and prior to indexing of the receiver. In some cases, an extra segment of wire is actually pulled from the wire dispenser or flyer and the grasped segment is released after at least some turns for a subsequent pole have been generated. Details of this type of procedure are spelled out in more detail in the above-referenced Arnold U.S. Pat. No. 3,967,658.
In one approach, as typified for example by the above-referenced Arnold U.S. Pat. No. 3,967,658, an interpole lead puller intercepts and grips a segment of an interpole lead wire or "interpole connection" as it is sometimes called in the art. After a complete set of coils or poles have been established in the coil receiving mechanism; equipment and approaches of the type taught in said referenced Arnold U.S. Pat. No. 3,967,658 will have established the interpole leads or "interpole connections" around the exterior or outer periphery of a receiving mechanism (clearly revealed, for example, in FIG. 5 of said referenced Arnold U.S. Pat. No. 3,967,658).
In still other approaches as taught, for example, in the above-referenced Smith U.S. Pat. No. 3,510,939; an interpole clamp is utilized (as represented for example by clamp means 84 in FIG. 1 of said referenced Smith U.S. Pat. No. 3,510,939) to establish an interpole lead that would be disposed within the interior of a coil receiving mechanism. When such mechanism is in the form of a circular array of longitudinally extending pins, the interpole wire or connection established by the just-mentioned Smith approach will occur within the bore defined by the circular array of blades, pins, or other gap establishing elements.
Whether the interpole connection or wire is disposed externally of or internally of the coil receiving mechanism depends upon a number of factors. For example, it may be preferred for some motor models or when using wire of a particular size to have the interpole connection or lead wire located externally of the coil receiving mechanism. On the other hand, in motors of other models or when using wire of other sizes, it may be preferred to establish the interpole wire or connection within the coil receiving mechanism. At least some problems are encountered and associated, however, with either of the approaches that have just been mentioned.
For example, when the interpole wire or connection is to be established exteriorly of the coil receiving mechanism as taught, for example, in the above-referenced Arnold U.S. Pat. No. 3,967,658; a relatively complex and therefore relatively expensive to produce and maintain mechanism must be provided in order to intercept a segment of wire at the desired time and thus establish the interpole wire or connection. On the other hand, when the relatively more simple and straightforward approach taught, for example, in the above-referenced Smith U.S. Pat. No. 3,510,939 is followed; the accuracy and reliability of the operation of the interpole wire clamping mechanism is critically dependent upon maintaining virtually infallible control over the position of the winding flyer (or other wire dispensing mechanism) at the instant that the clamping means is actuated. The reasons for the need to precisely and consistently control the flyer position and interrelate such position to actuation of a clamping means may be better understood with reference to the detailed description that is presented hereinbelow. For the moment, however, it should be understood that it would be desirable to provide new and improved methods and apparatus for use in developing dynamoelectric machine windings having at least two coil groups or poles interconnected by an interpole wire segment or connection such that the interpole wire segment is disposed interiorly of a turn receiving mechanism and yet wherein the critical interdependence of a flyer stopping position and operation of an interpole wire segment clamping device is eliminated. In other words, it would be desirable to provide improved methods and apparatus whereby an interpole wire segment or connection is established within a region having its outer boundaries established by a coil receiving means consistently and reliably virtually without regard to the final stopping position of a wire dispensing means relative to the position of the clamping means.
Accordingly, it is a general object of the present invention to provide new and improved methods and apparatus for establishing and handling segments of wire that interconnect coil groups (or poles) that are disposed in a winding turn receiver.
It is another object of the present invention to provide new and improved methods and apparatus that include provisions for establishing an interpole wire segment.
It is yet another general object of the present invention to provide new and improved methods and apparatus for developing two or more coil groups, two of which are interconnected by an interpole winding segment that is reliably and accurately positioned during a dwell or interruption of relative movement between a flyer and coil form assembly, but the formation of which is not dependent upon critical relative positioning between such flyer and coil form.
While the above discussion has been addressed primarily to "interpole" or "intercoil group" wire segments or connections; problems have also been long recognized in connection with precisely establishing "intercoil" winding segments "on the fly", and especially at elevated winding speeds in excess of, for example, 2,000 rpm. The problems associated with establishing suitable intercoil winding segments with consistent accuracy in shedder type winders are discussed, for example, in the above-referenced Lauer et al U.S. Pat. No. 3,765,081. Still another patent that discusses, among other things, problems associated with consistently accurate placement of intercoil winding segments is the above-referenced Arnold et al U.S. Pat. No. 3,973,601.
The importance of avoiding misplaced intercoil winding segments may be better understood and appreciated by referring to, for a moment, parts of the just-mentioned Arnold et al U.S. Pat. No. 3,973,601 and the just-mentioned Lauer U.S. Pat. No. 3,765,080.
As pointed out in the Arnold et al patent, shedder type winding equipment utilizes a turn receiving device and one or more coil forming parts that interfit with one another with relatively telescoping mutually cooperating relationships. Typically, winding turn receiving mechanisms with this kind of equipment establish or define turn receiving gaps or slots; and winding turns for a given coil are moved along predetermined ones of such gaps while each coil is being developed due to individual turns being generated about the winding forms. Each set of these predetermined gaps correspond with two predetermined slots of a stator core, and when an intercoil wire segment is inadvertently placed in the wrong gap, such misplaced wire segment will almost inevitably be broken when it ultimately is axially inserted into the stator core. Misplaced intercoil wire segments, as noted in both said Arnold et al and Lauer patents, have been the subject of diverse approaches in attempts to solve the problem. For example, intensive efforts have been made to increase the accuracy of the operational interrelationships of various parts, to improve such parts themselves, and to improve the relative movement and timing of such movement between such parts so that the winding turn receiving mechanism and coil forming mechanism may be axially moved relative to one another in a particular manner and at a particular time to overcome the misplaced intercoil wire segment problem. For example, many complex notches, ledges, and hooks have been provided on winding forms in order to insure that an intercoil wire segment will be provided in a desired relative location by insuring that a winding segment transitions from one coil form winding stage to another during the time that the winding forms are being advanced through the winding plane. Many efforts have also been made to insure that jumping of the coils forms relative to the winding turn receiving mechanism occurs precisely within optimum "windows" as defined, for example, in said Arnold et al patent.
Thus, it should now be understood that it is yet another object of the present invention to provide improved methods and apparatus for developing coil groups with shedder type winding equipment such that intercoil winding segments will be consistently and accurately positioned within a coil group without necessarily requiring concern for jump speed, complex winding form geometry, and undue concern for accomplishing coil form advancement only during a relatively small predetermined jump "window".